The Concept of Oligophagy and the Natural Habitats and Host Plants of Papilio machaon L. in Fennoscandia

Abstract In this paper a hypothesis is advanced according to which oligophagous insects have adopted two distinct strategies of habitat/host plant utilization, (1) a "monophagic strategy" being favoured in predictable habitats, making it possible to maximize reproductive success on one host plant per habitat only, (2) a "polyphagic strategy" being compulsively adopted in unpredictable habitats where two or more host plants per habitat have to be utilized for the maintenance of the species. For a partial preliminary test of this hypothesis the natural habitats and host plants of Papilio niachaon in Fennoscandia were investigated. The results indicate that (1) the predictable formations of inland wet-lands and coastal foreshores are the most important habitats (2) Peucedanum palustre, Angelica silvestris, Angelica archangelica ssp. littoralis and norvegica are the dominant host plants and (3) P. machaon appears to have adopted a "monophagic strategy" of habitat/host plant utilization in the predictable habitat categories.